Working poor families, who earn less than 200% of the federal poverty level, have long been overlooked by researchers and policy makers. Despite their low earnings, adults in these families have not relied on public assistance and historically have not qualified for means-tested insurance programs such as Medicaid. As a result, working poor families, many of whom do not receive health insurance benefits through their employer, have had difficulties accessing healthcare and meeting their healthcare needs. With welfare reform setting short lifetime limits on the receipt of welfare and imposing work requirements, more families are transitioning into the ranks of the working poor. Even though California is the most expensive state to reside in, its working poor families (18% of the state population) have the lowest average income in the nation. In California, a large proportion of working poor families are immigrants. Evidence suggests that immigrant working poor children experience even greater difficulties in access to care. In an effort to minimize these disparities, California has recently expanded health insurance coverage for eligible working poor children and their parents. Yet there has been no population-based study to monitor the impact of these expansions. The proposed study will analyze data from the 2001 California Health Interview Survey (CHIS) in an aim to fill gaps in knowledge of the extent to which children of the working poor access and utilize health services. Specifically, it will 1) compare access and utilization of healthcare among working poor children with children in other socioeconomic strata; 2) explore the differences in access and utilization of healthcare between immigrant and native born children of the working poor; and 3) assess the extent to which expansions in health coverage for working poor parents can improve access and use of health services for their children. CHIS, the largest cross-sectional state health survey of the civilian population ever conducted in the US, offers an excellent opportunity to examine healthcare access for working poor families. The sampling frame, language capabilities, and 70% response rate for adults indicate that the data are likely to be representative of the California population. Because this is the first large-scale data collection effort since California expanded health insurance access for the working poor, CHIS data will allow this study to monitor the extent to which these policies have affected access to and use of healthcare and the extent to which, by expanding insurance coverage for parents, children's access to care may also improve. Further, it will allow for an assessment of the extent to which legal status influences access to and use of health services for working poor immigrants in California. This study will help policy makers understand the determinants of access to care and use of health services as a first step towards assessing the quality of care for children of the working poor.